At present using an H-shifter if you change into 6th/7th etc with your H shifter and the car is only 5 speed it will select 5th.

This should be updated so that it remains in N as the gear you have selected is not valid.

or it could be intended to be that way and threfore not a bug at all.

I think that the current behaviour is the correct one also

I agree with Woz, it's weird that I can miss the reverse notch and end up with 5th in a 5 gear car, with the stick in the 6th position.

It is most likely intended behaviour but I'm not convinced it's the best way to handle the situation.

IRL, if you were driving a 5 speed car you would have a 5 speed shifter. I think it's perfectly fine for the gear to stay in 5th.